• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.100-109
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• 2019

Maintainability indicates the extent to which maintenance can be done easily and quickly. The consideration of maintainability is crucial to reduce the operation and support costs of weapon systems, but if the maintainability is evaluated after the prototype production is done and necessitates design changes, it may increase the cost and delay the schedule. The evaluation should verify whether maintenance work can be performed, and support the designers in developing a design to improve maintainability. In previous studies, the maintainability index was calculated using the graph theory at the early design phase, but evaluation accuracy appeared to be limited. Analyzing the methods of evaluating the maintainability using fuzzy logic and 3D modeling indicate that the design of a system with good maintainability should be done in an integrated manner during the whole system life cycle. This paper proposes a method to evaluate maintainability using SysML-based modeling and simulation technique and fuzzy logic. The physical design structure with maintainability attributes was modeled using SysML 'bdd' diagram, and the maintainability was represented by an AHP matrix for maintainability attributes. We then calculated the maintainability using AHP-based weighting calculation and fuzzy logic through the use of SysML 'par' diagram that incorporated MATLAB. The proposed maintainability model can be managed efficiently and consistently, and the state of system design and maintainability can be analyzed quantitatively, thereby improving design by early identifying the items with low maintainability.

• Journal of the Korean Orthopaedic Association
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• v.53 no.6
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• pp.478-489
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• 2018

Total knee arthroplasty has become a standard procedure for advanced knee arthritis to relieve pain and improve function. Computer-assisted navigation systems have been used in total knee arthroplasty to improve the mechanical axis of the limb as well as the alignment and position of the components. A computer-assisted navigation system has the advantage of real-time feedback during surgery, such as mediolateral balance in extension and flexion gap, alignment of the lower limb, and components. On the other hand, the computer-assisted navigation system requires an additional stab wound for tracker fixation, which can increase the likelihood of superficial wound infection and stress fractures and increase the operation time and cost of surgery. The clinical efficacy of computer-assisted navigation in total knee arthroplasty is also controversial. Compared to the conventional technique, computer navigation improves the accuracy of the postoperative mechanical axis within outliers of $3^{\circ}$ varus or $3^{\circ}$ valgus. This paper reviews the surgical technique, pitfalls, clinical and radiological outcomes, useful clinical cases, and future perspectives in computer-assisted navigation total knee arthroplasty.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.243-246
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• 2016

Data transfer technique is one of the key elements of the IT infrastructure, in accordance with each environment and function, using some kind of protocol. Using the three protocols such as WCDMA, AIS, and TRS at sea IT industry. so It uses three protocols saw has a problem that the operation of each protocol-specific server. so server maintenance costs increase and sea Device Manager has been placed in a situation which operates to develop each of the protocol-specific analysis program. The reason of the protocol is divided into three, marine equipment (lighthouses, buoys, light buoy) manufacturing companies and the date of manufacture, such as, communication environment (distance, communication speed) because such is wrong all, trying to unify this and enormous cost and time is a situation that can not be the exchange occurred when. So in the Ministry of Maritime Affairs and Fisheries, the number of frequency of use is low, communication performance is seeking to refrain from Kure each local organizations and companies the use of low TRS protocol. his paper is intended to conduct research on the basis of the actual data to analyze whether the method is how economical to store a single DB by analyzing other types of protocols. This reduces the shortage of marine IT industry, even a little, shall helps reduce administrative costs.

• World Technopolis Review
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• v.8 no.1
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• pp.59-70
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• 2019

Where is a better place to live? In the coming era, this should be more than simply a livable place. It should be an adaptable place that has a flexible system adaptable to any new situation in terms of diversity. Customization and real-time operation are needed in order to realize this technologically. We expect a smart city to have a flexible system that applies technologies of self-monitoring and self-response, thereby being a promising city model towards being a better place to live. Energy demand and supply is a crucial issue concerning our expectations for the flexible system of a smart city because it is indispensable to comfortable living, especially city living. Although it may seem that energy diversification, such as the energy mix of a country, is a matter of overriding concern, the central point is the scale of place to build grids for realizing sustainable urban energy systems. A traditional hard energy path supported by huge centralized energy systems based on fossil and nuclear fuels on a national scale has already faced difficult problems, particularly in terms of energy flexibility/resilience. On the other hand, an alternative soft energy path consisting of small diversified energy systems based on renewable energy sources on a local scale has limitations regarding stability, variability, and supply potential despite the relatively light economic/technological burden that must be assumed to realize it. As another alternative, we can adopt a holonic path incorporating an alternative soft energy path with a traditional hard energy path complimentarily based on load management. This has a high affinity with the flexible system of a smart city. At a system level, the purpose of all of the paths mentioned above is not energy itself but the service it provides. If the expected energy service is fixed, the conclusive factor in choosing a more appropriate system is accessibility to the energy service. Accessibility refers to reliability and affordability; the former encompasses the level of energy self-sufficiency, and the latter encompasses the extent of energy saving. From this point of view, it seems that the small diversified energy systems of a soft energy path have a clear advantage over the huge centralized energy systems of a hard energy path. However, some insuperable limitations still remain, so it is reasonable to consider both energy systems continuing to coexist in a multiplexing energy system employing a holonic path to create and maintain reliable and affordable access to energy services that cover households'/enterprises' basic energy needs. If this is embodied in a smart city concept, this is nothing else but smart energy inclusion. In Japan, following the Fukushima nuclear accident in 2011, a trend towards small diversified energy systems of a soft energy path intensified in order to realize a nuclear-free society. As a result, the Government of Japan proclaimed in its Fifth Strategic Energy Plan that renewable energy must be the main source of power in Japan by 2050. Accordingly, Sony vowed that all the energy it uses would come from renewable sources by 2040. In this situation, it is expected that smart energy inclusion will be achieved by the Japanese version of a smart grid based on the concept of a minimum cost scheme and demand response.

• Korean Journal of Heritage: History & Science
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• v.51 no.2
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• pp.124-137
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• 2018

Although the evaluation system for excavation reports has been in operation for over 10 years, there has been no research on the evaluation system. First, this study examined the changes of the evaluation system, and secondly, it analyzed the evaluation factors affecting the evaluation results. As a result of institutional analysis, the present evaluation result is being utilized in PQ, and it is suggested that the evaluation subject institution is limited to the excavation institution, which may cause disadvantages to the participating museums. We also pointed out that a small number of jury members are currently evaluating the report and therefore need to reinforce it to ease the burden of assessment. As a result of evaluation factor analysis, it was confirmed that the target score was lower but the actual effect score was higher. In addition, it suggested that the indicators should be improved because the report system, headings, natural archaeological environment, scope and method of survey, and editing and printing indicators are less influential than other indicators. In addition, we conducted a regression analysis of each group by examining the appropriateness of classification amounts according to current excavation costs. As a result of the analysis, the cost of excavation in the second and third groups in 2015 and 2016 was found to affect the score. This emphasized the need for an in-depth approach to estimating the taxonomic value of the group, which is inconsistent with the initial objective of not affecting the assessment results according to excavation costs.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.5
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• pp.609-616
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• 2019

When the fouling of a vessel occurs, its resistance at sea increases and there is a corresponding increase in fuel consumption. The maintenance cost of the vessel also increases because it is time-consuming to remove the fouling. To solve this problem and minimize environmental contamination of sea-water, there have been recent developments in anti-fouling paints as self-polishing copolymers that not include toxic elements such as tin. When these conventional techniques are applied to vessels, polishing is promoted during the operation whereby friction or vibration with seawater occurs. This leads to enhanced anti-fouling performance. However, when fouling is intensified such as during an anchorage, there is no flow of seawater and polishing is suppressed. This leads to a deterioration of the performance of anti-fouling. To solve these problems, we developed a system that induces vibration in a vessel during anchorage. As such, the deterioration of polishing due to insuf icient flow of seawater is inhibited. The reliability of the ultrasonic antifouling system was evaluated by calculating its repeatability. The removal efficiency of fouling of the proposed system was qualitatively evaluated using test specimens. The test revealed that the value of the coefficient of variation for the reproducibility of the frequency and amplitude was 0.2 % and 4.0 % on average. The degree of fouling of the specimens was the highest at 73.3 g in the No.5 sepcimen. Moreover, efficiency of fouling removal was 93.2 % on average compared to the specimens without the proposed system.

• Industry Promotion Research
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• v.4 no.1
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• pp.79-86
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• 2019

The quality of service delivery by governments to their citizens is a subject of concern in the contemporary society. E-governance is a critical aspect that is transforming government operation and service delivery to citizens and other bodies through application of information technology. This research explores the state of e-governing focusing on nations that are developing with special attention to Pakistan. The difficulties and benefits encountered are identified. The results are vital for implementers of e-governing systems in these countries. The methodology applied entails a secondary research that involves analysis and synthesis of literature relating the research topic. The results reveal that Pakistan has made incredible steps in setting up e-governance systems with growth in internet use and access of data from a digital platform. The findings reveal that e-government is associated with multiple benefits including enhanced quality of services, cost efficiency in service provision, enhance transparency and elimination of corruption, provide the basis for eradication of poverty, boost economic stability of a country, and provide room for direct democracy. The research also found that developing countries experience challenges in form of financial constraints, poor ICT infrastructure, illiteracy on e-government, political consensus constraints, legal obstacles, social and cultural constraints. E-government has the capability to transform the quality of governance provided by governments, and policymakers and implementers should address the constraints that act as a hindrance to its implementation.

• Explosives and Blasting
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• v.36 no.4
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• pp.1-8
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• 2018

This numerical study was intended to evaluate the applicability of the half charge blasting to mining and tunnelling. The half charge blasting is a method that two separate rounds are sequentially blasted for the rock burdens in which long blast holes have already been drilled at one operation. The aim of the method is to decrease the construction cost and period in mining and tunnelling projects as well as to increase the blasting efficiency. Several numerical analyses were conducted by using the Euler-Lagrange solver on ANSYS AUTODYN to identify the effects of the suggested method on the blasting results in underground excavations. The overall performance of the suggested method was also compared to an ordinary blasting method. The analysis model was comprised of the Eulerian parts (explosive, air, and stemming materials) and the Lagrangian parts (rock material). As a result, it was found that, owing to the air decks formed in the bottom parts of the long blast holes, the first round of the suggested method presented a higher shock pressure and particle velocities in the vicinity of the blast holes compared to the ordinary blasting method.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.3
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• pp.419-432
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• 2019

Most of deep learning model training was proceeded by supervised learning, which is to train labeling data composed by inputs and corresponding outputs. Labeling data was directly generated manually, so labeling accuracy of data is relatively high. However, it requires heavy efforts in securing data because of cost and time. Additionally, the main goal of supervised learning is to improve detection performance for 'True Positive' data but not to reduce occurrence of 'False Positive' data. In this paper, the occurrence of unpredictable 'False Positive' appears by trained modes with labeling data and 'True Positive' data in monitoring of deep learning-based CCTV accident detection system, which is under operation at a tunnel monitoring center. Those types of 'False Positive' to 'fire' or 'person' objects were frequently taking place for lights of working vehicle, reflecting sunlight at tunnel entrance, long black feature which occurs to the part of lane or car, etc. To solve this problem, a deep learning model was developed by simultaneously training the 'False Positive' data generated in the field and the labeling data. As a result, in comparison with the model that was trained only by the existing labeling data, the re-inference performance with respect to the labeling data was improved. In addition, re-inference of the 'False Positive' data shows that the number of 'False Positive' for the persons were more reduced in case of training model including many 'False Positive' data. By training of the 'False Positive' data, the capability of field application of the deep learning model was improved automatically.

• Journal of Korean Neurosurgical Society
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• v.64 no.2
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• pp.297-308
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• 2021

Objective : Shunt infection is a common complication while treating hydrocephalus. The antibiotic-impregnated shunt catheter (AISC) was designed to reduce shunt infection rate. A meta-analysis was conducted to study the effectiveness of AISCs in reduction of shunt infection in terms of age, follow-up time and high-risk patient population. Methods : This study reviewed literature from three databases including PubMed, EMBASE, and Cochrane Library (from 2000 to March 2019). Clinical studies from controlled trials for shunt operation were included in this analysis. A subgroup analysis was performed based on the patient's age, follow-up time and high-risk population. The fixed effect in RevMan 5.3 software (Cochrane Collaboration) was used for this meta-analysis. Results : This study included 19 controlled clinical trials including 10105 operations. The analysis demonstrated that AISC could reduce the infection rate in shunt surgery compared to standard shunt catheter (non-AISC) from 8.13% to 4.09% (odds ratio [OR], 0.48; 95% confidence interval [CI], 0.40-0.58; p=0.01; I2=46%). Subgroup analysis of different age groups showed that AISC had significant antimicrobial effects in all three groups (adult, infant, and adolescent). Follow-up time analysis showed that AISC was effective in preventing early shunt infections (within 6 months after implant). AISC is more effective in high-risk population (OR, 0.24;95% CI, 0.14-0.40; p=0.60; I2=0%) than in general patient population. Conclusion : The results of meta-analysis indicated that AISC is an effective method for reducing shunt infection. We recommend that AISC should be considered for use in infants and high-risk groups. For adult patients, the choice for AISC could be determined based on the treatment cost.